By-products discharged from processed products of aquaculture are currently rising, driven by both a net increase in seafood products consumption and the changing consumer trends towards ready-to-use products. However, these by-products may be a source of high added value compounds which can be employed in many applications. In this regard, mussel byssus is a by-product from mussel production for human consumption and it has been demonstrated that mussel byssus is an amazing source of marine collagen. Therefore, the objective of this study was to develop a method for collagen extraction from the mussel byssus as a potential new source of collagen for food or pharmaceutical uses. The proposed procedure for the extraction of collagen from mussel byssus consists in two pre-treatments and one extraction step. The first pre-treatment was an alkaline pre-treatment using NaOH, and the second one was an acid pre-treatment using HCl. The extraction step consisted in the immersion of byssus in an acetic acid solution (pH 4.0) at two temperatures (60 or 80°C) and two times (6 or 24 h). A previous enzymatic step (4 or 24 h) using pepsin (20 or 80 mg/g sample) was done for the extraction at 80°C for 24 h. Total protein, aminoacid profile and molecular weight of collagen extracts were quantified by spectrophotometry (Bradford test), HPLC and electrophoresis, respectively. Extraction time and temperature had an strong effect over the protein content after the acid extraction step, with the high levels of process parameters given the highest content of protein (6 [mg/ml]) and hydroxyproline (0.482 [mg/ml]). For all conditions the enzymatic step increased the protein and hydroxyproline content with an average value of 27 (mg/ml) and 1.8 (mg/ml), respectively. In addition, acid and pepsin-soluble collagen had the same banding patterns of bovine collagen. Higher levels of temperature and time of the extraction step gave the highest values of total protein and hydroxyproline. For all conditions the enzymatic step increases the final protein and hydroxyplroline content.
Principal investigator: Rommy N. Zúñiga rommy.zuniga@utem.cl
